The NLD cannot threaten the army-backed party's ruling majority even if it wins all 48 seats, but the vote has important symbolic value as the first time Suu Kyi has been able to directly participate in a Myanmar election.

"I would like to ask for people to believe in us, as we respect and cherish the people," Suu Kyi told the crowds gathered for her speech in one of the constituency's villages.

"Without the support of the people, no organisation and nobody can work for the benefit of the country. We can win anything if the people are involved in it."

A widely-expected win for Suu Kyi would lend strong legitimacy to the country's parliament, which first convened earlier last year and is dominated by former generals who kept her in detention for much of the past two decades.

"I'm very glad I can see her," said 31-year-old housewife Nang Naing Naing Oo after Suu Kyi visited her village. "I expect she will work not just for one village but for the development and success of the whole country."

The NLD won a landslide victory in an election in 1990, but the then-ruling junta never allowed the party to take power. Suu Kyi was a figurehead for the party's campaign despite being under house arrest at the time.

She was released from her latest stint in detention a few days after a much-criticised election in 2010.

Ahead of the campaign day, Suu Kyi insisted her party - which boycotted the 2010 election - was taking nothing for granted.

"We will work very hard to win all 48 seats. It's not a matter of expectations, it's a matter of hard work," the Nobel Peace Prize winner said.

Controversy surrounding the 2010 vote means the by-elections will be heavily scrutinised.